We wish to initiate studies on several strains of Actinomyces viscosus with the objective of providing basic information concerning peripheral structural elements of the bacterial cell wall. These peripheral elements are responsible for various cell surface related properties such as cell adhesion and immunological response. The first part of the study will be concerned with an extensive study of catabolic enzymes (glycohydrolases) capable of degrading the cell wall. Special emphasis will be placed upon the removal of peripheral cell wall components. Similarly, the catabolic degradation of extracellular polysaccharides of Actinomyces viscosus will be studied. In a second complementary study to the above approach, we will concern ourselves with the biosynthesis of immunodeterminant sugars in Actinomyces viscosus and the incorporation of these sugars into the cell wall. Various attempts will be made to interfere with synthesis and/or incorporation of sugars into the cell wall. The main objective of these studies will be to provide a rational biochemical basis to cause change in the peripheral structural elements of the cell wall and to test these changed cells for their altered biological response such as adhesion of bacterial cells to the tooth surface and immuno response.